Fix MySQL DELETE using CONCAT_WS preventing index usage #3940

Job	Run time
changes	7s
test-dbt-versions (1.5)	1m 36s
test-dbt-versions (1.8)	1m 43s
test-dbt-versions (1.3)	1m 38s
test-dbt-versions (1.4)	1m 34s
test-dbt-versions (1.6)	1m 45s
test-dbt-versions (1.10)	1m 43s
test-dbt-versions (1.9)	1m 53s
test-dbt-versions (1.7)	1m 46s
test-vscode-e2e	0s
test-vscode	0s
doc-tests	33s
cicd-tests-windows	13m 17s
style-and-cicd-tests (3.13)	23m 31s
style-and-cicd-tests (3.9)	24m 1s
migration-test	1m 32s
style-and-cicd-tests (3.12)	25m 1s
style-and-cicd-tests (3.11)	23m 54s
style-and-cicd-tests (3.10)	26m 15s
engine-tests-docker (mssql)	1m 49s
engine-tests-docker (postgres)	2m 22s
engine-tests-docker (mysql)	1m 41s
engine-tests-docker (duckdb)	1m 34s
engine-tests-docker (starrocks)	3m 10s
engine-tests-docker (clickhouse)	3m 3s
engine-tests-docker (trino)	8m 51s
engine-tests-docker (spark)	6m 43s
engine-tests-docker (risingwave)	2m 49s
ui-test	-1s
ui-style	-1s
engine-tests-cloud	-1s
	3h 3m 48s

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